Method for conveying, guiding, and locating a thermoformable web

ABSTRACT

A method for delivering web-supported articles between dies and punches of a trim press. The method includes providing a treadle having an article detector, while moving the web and the articles, guiding the web and the articles along the web and between a pair of the articles each provided in one of a pair of adjacent rows that extend along a travel path direction, detecting location of an article in the web using the article detector, and in response to detecting the location of the article, controllably moving the web to position the article between a corresponding punch and die of the trim press.

RELATED PATENT DATA

[0001] This patent application is a divisional application of U.S.patent application Ser. No. 09/686,714, filed Oct. 10, 2000, initiallyentitled “Apparatus and Method for Conveying, Guiding, and Locating aThermoformable Web” and later amended to “Apparatus for Conveying,Guiding, and Locating a Thermoformable Web”, naming Jere F. Irwin asinventor, and which is now U.S. Pat. No. ______ , the disclosure ofwhich is incorporated by reference.

TECHNICAL FIELD

[0002] The present invention pertains to an apparatus and method forhandling a thermoformed sheet or web of plastic or foam materialcontaining thermoformed thin-walled articles when separating thearticles from the web. More particularly, this invention relates to atrim press article handling apparatus such as a conveyor having atreadle in the form of a web and article conveying, guiding, andlocating device.

BACKGROUND OF THE INVENTION

[0003] Various devices are known for trimming thin-walled articles fromsheets of thermoformed plastic material. The trimming or severing ofsuch articles from a continuous sheet of thermoformable plastic and/orfoam material has long been known in the art. Additionally, sheet guidesand mechanical treadles are known for moving the sheet and articles forintermittent severing between coacting punches and dies of a trim press.

[0004] U.S. Pat. No. 4,173,161 discloses a mechanical trim press thatincludes a mechanical treadle having feed fingers mounted on thetreadle. The feed fingers comprise a mechanical linkage that interactswith projecting integral tabs formed in the sheet to advance the sheetto a die in step-by-step movement that is mechanically synchronized withthe stroke of the punch. The treadle also includes opposed pairs ofvertical guide strips between each article. Each guide strip is carriedby a spacer that is mounted onto a cross frame member of the treadle.Opposed pairs of guide strips, provided between each adjacent pair offormed articles in the sheet, are spaced apart slightly from each otherby a distance slightly greater than the thickness of the sheet passingtherebetween. However, such close spacing coupled with the use of guidestrips between every adjacent pair of articles results in increasedfrictional forces which tends to result in mis-feeding and jamming ofthe treadle, particularly when running the treadle at relatively highproduct feed rates.

SUMMARY OF THE INVENTION

[0005] A treadle device is provided for conveying, guiding, and locatingweb-supported articles or products during a web processing operation.More particularly, a treadle assembly guides web-supported articles intoa trim press prior to and while severing the articles from the web. Suchtreadle device provides accurate location of articles while moving theweb and reducing frictional forces generated between the treadle and webwhich would otherwise result in an increased occurrence of mis-feeds andmisalignment of the web and articles, particularly during relativelyhigh speed trim operations. An additional degree of accuracy is alsoprovided during such severing operation over that previously providedvia use of accurate high speed conveying, guiding, and locatingtechniques. Additionally, feedback controlled operation is maintained todrive a servo pick and servo helper of a web feed delivery deviceassociated with the treadle and trim press.

[0006] According to one aspect, a method is provided for deliveringweb-supported articles between dies and punches of a trim press,including: providing a treadle having an article detector; while movingthe web and articles, guiding the web and articles along the web andbetween a pair of articles in a row extending transverse to a travelpath direction; detecting location of an article in the web using thearticle detector; in response to detecting the location of the article,controllably moving the web to position the article between acorresponding punch and die of the trim press.

[0007] According to another aspect, a method for delivering a web ofmaterial having articles formed therein between a die and punch of atrim press, the method includes guiding the web between the die and thepunch, the die and the punch being provided in a travel path of the web,providing a treadle having an article detector, the treadle beingconfigured to move relative to the die and the punch, detecting alocation of an article in the web using the article detector, andcontrollably moving the web, in response to the detecting, to positionthe article between the punch and the die to perform severing andtrimming of the article.

[0008] According to a further aspect, a method for delivering a web ofmaterial having articles formed therein between a die and punch of atrim press. The method includes guiding the web between the die and thepunch, providing and configuring a treadle to move relative to the dieand the punch, detecting a location of an article in the web, andcontrollably moving the web, in response to the detecting, to positionthe article between the punch and the die to perform severing andtrimming of the article.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0010]FIG. 1 is a vertical side view of a thermoforming machine trimpress having a treadle conveying, guiding, and locating device embodyingone aspect of the invention.

[0011]FIG. 2 is a simplified partial perspective view of the treadle ofFIG. 1 and illustrates an article sensing device provided by thetreadle.

[0012]FIG. 3 is a simplified sectional view taken generally along line3-3 of FIG. 2 but including the trim press punch plate and die plate ofFIG. 1 and further showing the control system and servo pick conveyor.

[0013]FIG. 4 is an enlarged, simplified sectional view of the primaryguide member and web guide plate taken generally along line 3-3 of FIG.2 and including a web containing articles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0015] Reference will now be made to a preferred embodiment ofApplicant's invention. One exemplary implementation is described belowand depicted with reference to the drawings comprising an articleconveying, guiding, and locating device and method for aligning articleswithin a web of thermoformable material for a severing operation. Whilethe invention is described by way of a preferred embodiment, it isunderstood that the description is not intended to limit the inventionto this embodiment, but is intended to cover alternatives, equivalents,and modifications such as are included within the scope of the appendedclaims.

[0016] In an effort to prevent obscuring the invention at hand, onlydetails germane to implementing the invention will be described in greatdetail, with presently understood peripheral details being incorporatedby reference, as needed, as being presently understood in the art.

[0017] A preferred embodiment of Applicant's invention is shown on athermoforming machine trim press having a treadle system that isgenerally designated with reference numeral 10 in FIG. 1. Moreparticularly, treadle system 10 is provided on a trim press 12 toaccurately convey, guide, and locate articles 14 formed within a sheet,or web, 16 of thermoformable material during an article trim operationthat severs articles 14 from web 16. Treadle system 10 is operative tointermittently convey and align articles 14 so as to successively severrows of such articles 14 from the web 16.

[0018] A control system 18 of treadle system 10 choreographs operationof trim press 10 acting in unison with a servo motor driven conveyor 20that includes a servo pick assembly 60 and a servo helper assembly 62.Conveyor 20 moves web 16 in which individual articles, or products, 14have previously been formed using a thermoforming machine (not shown).In operation, web 14 is driven in intermittent motion using controlsystem 18 and conveyor 20 to successively feed individual rows ofarticles 14 into trim press 12 where the articles 14 are severed fromweb 16. During closure of trim press 12, treadle 10 aids in accuratelypositioning articles 14 with respect to punch and die members 22 and 24just prior to severing articles 14 from web 16.

[0019] Further details of one exemplary trim press similar to trim press12, but configured in a vertical orientation are disclosed inApplicant's copending U.S. patent application Ser. No. 09/576,219,entitled “Article Stacking Device, Trim Press Article Accumulator, andMethod of Stacking Thermoformed Articles”, naming Jere F. Irwin asinventor. Such U.S. patent application Ser. No. 09/576,219 is hereinincorporated by reference. Trim press 12, as depicted herein, is amodified version of Applicant's commercially available trim press “Model28NT Trim Press”, sold by Irwin Research and Development, of Yakima,Wash. The modifications entail adding the novel control system 18,conveyor assembly 20, and treadle system 10.

[0020] In order to improve the speed and accuracy with which articles 14are severed from web 16 by trim press 12, treadle 10 is provided on trimpress 12 incorporating desired features of Applicant's invention.Treadle 10 provides highly accurate article conveying, guiding, andlocating when delivering web-supported articles between punches 22 anddies 24 of trim press 12.

[0021] Trim press 12 includes a movable platen 26, a stationary platen28, a punch plate 30, and a die plate 32. Punch plate 30 is carried formovement by movable platen 26, whereas die plate 32 is fixedly carriedby stationary platen 28. However, it is understood that platen 28 anddie plate 32 can also be movably supported for operation according to analternative construction.

[0022] As shown in FIG. 1, movable platen 26 is carried for horizontalreciprocation by crank arm assemblies 34-37. Details of one exemplarythermoforming machine suitable for incorporating treadle 10 and havingsuch crank arm assemblies are shown in U.S. patent application Ser. No.08/691,856, now U.S. Pat. No. 6,067,886, entitled “Machine Trim PressHaving Counterbalance Features”, and naming the inventor as Jere F.Irwin. Such U.S. Pat. No. 6,067,886 is herein incorporated by reference.

[0023] An electric servo motor 31 drives crank arm assemblies 34-37 viaa transfer case assembly 33 including a pair of connected transfer casesand a respective pair of rotating drive shafts 39, 41 similar to thosedisclosed in U.S. Pat. No. 6,067,886, previously incorporated byreference.

[0024] Each crank arm assembly 34-37 comprises a throw arm 38 and aplaten connecting rod 40, wherein arm 38 and rod 40 cooperate to form akinematic linkage that drives a dedicated corner of platen 26 forhorizontal, guided reciprocation. Additionally, two cylindrical,stationary guide posts (not shown) are rigidly carried by a frame 42 tosupport platen 26 for movement in an axial, horizontal direction.Optionally, four guide posts can be configured to support platen 26 withtwo corresponding bronze bushings. The use of platen guide posts isunderstood in the art. Accordingly, such guide posts have been omittedfrom the figures in order to simplify the drawing and to preventobscuring the invention at hand.

[0025] Additionally, a pair of stationary, cylindrical guide posts 44,46 are rigidly supported by frame 42 to guide horizontal, reciprocatingmovement of treadle 10 relative to frame 42 and stationary platen 28.Bronze bushings 48 and 50-51 on treadle 10 are affixed to a frame 52 oftreadle 10, and are configured to slide along guide posts 44, 46,respectively.

[0026] Stationary guide members 54 and 56, in the form of pairs of edgeguide tracks and central guide tracks, form a self-feeding canopy 49that guides web 16 and articles 14. More particularly, guide members 54and 56 guide and move web 16 and articles 14 from a thermoformingmachine (not shown), positioned upstream of trim press 12, downwardlyinto treadle 10 and between punch plate 30 and die plate 32 for severingarticles 14 from web 16 therebetween.

[0027] Web conveyor assembly 20 moves web 16 and articles 14 along guidemembers 54 and 56 and through treadle 10. Web conveyor 20 comprises aservo pick assembly 60 and a servo helper assembly 62. Servo pickassembly 60 is carried by treadle 10, whereas servo helper assembly 62is carried by guide member 54. Accordingly, servo pick assembly 60 iscarried for movement relative to stationary servo helper assembly 62.

[0028] As shown in FIG. 1, web conveyor assembly 20 is illustrated insimplified form. More particularly, servo pick assembly 60 and servohelper assembly 62 are each depicted as a drive wheel assembly 64, 66,wherein each includes a servo motor (not shown) that is controllablyactuated via a control system 18 to impart intermittent motion thatfeeds web 16 into trim press 12.

[0029] Servo pick assembly 60 and servo helper assembly 62, according toone construction, each include a Siemens servo motor Model Part No.1FT5062-1AC71-4FA0, commercially available in the United States fromSiemens Energy & Automation, of Atlanta, Ga. Additionally, the servomotors for servo pick assembly 60 and servo helper assembly 62 eachfurther includes a rotary encoder which is used in conjunction with theservo motor as a feedback signal to detect motion of drive wheels 72 and78 in order to directly measure the amount of feed imparted by servohelper assembly 62 relative to the feed of servo pick assembly 60.Accordingly, the servo helper assembly is synchronized in relation tothe speed of the servo pick assembly.

[0030] According to prior art techniques, a servo pick assembly wasutilized with a helper assembly having a variable speed motor. Thevariable speed motor was regulated so as to deliver a distance of web atleast as much as that which is moved by the servo pick assembly. Anaccumulation region was provided along guide member 54 to accumulate anyexcess web which is overfed by the helper assembly, wherein the helperassembly is driven by the variable speed motor which is run at a speedthat delivers a web equal to or greater in quantity than that deliveredby the servo pick assembly. Hence, the accumulation of web and articlesoccurs along the guide member. However, the buildup of excess sheetthere along has a tendency to bounce the sheet and articles around,which can cause misalignment problems and cause a reduction in themaximum operating speed for the conveyor. Accordingly, synchronizationof a servo helper assembly with a servo pick assembly leads to increasedproduct throughput rates. Such result is realized because the motor onthe servo helper assembly can duplicate a nearly identical motion as themotor on the servo pick assembly since both motors comprise servomotors.

[0031] Additionally, a photo proximity switch 112 is carried by guidemember 56, beneath one edge of web 16 for detecting the proximity of web16 in relation to guide member 56. More particularly, switch 112comprises a Model No. E51-Q25FN6FF100Q sensor, otherwise referred to asan Easy-Easy-Beam Q25 Series sensor, sold commercially by BannerEngineering Corporation of Minneapolis, Minn. Such a photo proximityswitch has a focal range that monitors the proximity of web 16. When theweb is within a focal point range of approximately four inches, adigital output is generated. When the focal point exceeds theapproximately four-inch range, a different digital value is generatedand delivered to control system 18. Accordingly, control system 18monitors the proximity of web 16 relative to guide member 56 of canopy49. When a significant amount of detected separation occurs between web16 and guide member 56, control system 18 reduces the operating speed ofdrive wheels 78 for servo helper assembly 62. Accordingly, the deliveryspeed of servo helper assembly 62 relative to servo pick assembly 60 iscontrollably regulated by control system 18 in response to the signaldetected by photo proximity switch 112. Alternatively, it is understoodthat any of a number of other proximity switches can be utilized, suchas proximity mode ultrasonic sensors, or optical detectors.

[0032] By controllably regulating the operating speed of drive wheels 78relative to drive wheels 72, the accumulation of web 16 therebetween issubstantially prevented.

[0033] Accordingly, the need for a substantial accumulation area alongguide member 54 is eliminated. Furthermore, motion of the web andarticles is monitored at treadle 10 via article detector 80 and controlsystem 18. For cases where servo helper assembly 62 does not exactlymimic the delivery rate for the servo pick assembly 60 or whenmisalignment is detected or likely to occur, control system 18 brieflyand quickly opens or raises follower wheel 76 away from drive wheel 78using a pneumatic cylinder which raises each follower wheel 76 alongopposite edges of web 16. Hence, opening of follower wheels 76 for avery short period of time while trim press 12 is open enablesrealignment of the web and adjustment and spacing of the web betweendrive wheel assembly 64 and drive wheel assembly 66. For example, suchopening in one case lasts 0.07 seconds. Such brief opening, actuated viapneumatic cylinders and control system 18, achieves minor corrections inthe length and alignment of web positioned between drive wheelassemblies 64 and 66 which accounts for any minor variations in theamount of web delivered by servo pick assembly 60 and servo helperassembly 62. Accordingly, such correction is only implemented inresponse to monitoring of web and article delivery utilizing articledetector 80 and/or switch 112. Alternatively, such correction can beimplemented periodically, such as after every five trim press cycles.

[0034] According to one construction, optical beam 108 (see FIG. 3)detects locations of articles 14 by detecting the positioning of anarticle that interrupts beam 108. Alternatively, web 16 can includeprotuberances specifically designed to interrupt optical beam 108 andthermoformed into web 16 at a location known relative to articles 14.Accordingly, optical beam 108 can be utilized to detect suchprotuberances in order to locate the positioning of articles 14 relativeto plate 100. Accordingly, articles 14 form one of a number of differenttypes of protuberances within web 16 which are detected via optical (orlight) beam 108.

[0035] As shown in FIG. 1, drive wheel assembly 64 comprises two pairsof co-acting wheels that are provided along opposite side edges of web16. An outermost wheel of each pair comprises a follower wheel 70 and aninnermost wheel of each pair comprises a drive wheel 72. The pair ofdrive wheels 72 are driven by a common servo motor using a splined shaft(not shown) that extends between the drive wheels and drives each wheelusing a splined drive wheel attached to each drive wheel 72 thatattaches to the splined shaft via a correspondingly splined drive belt.Accordingly, each drive wheel 72 is actuated and driven by a commonservo motor.

[0036] Accordingly, actuation of drive wheel assembly 64 via controller68 is operative to intermittently deliver rows of articles 14 into trimpress 12. Such rows of articles 14 are then severed as control circuitry68 of central system 18 actuates a severing operation via trim press 12.Subsequently, a scrap web 74 is delivered from trim press 12 and groundinto small pieces using a comminuting device (not shown) configured forgrinding up scrap web 74 and positioned beneath trim press 12.

[0037] Similarly, drive wheel assembly 66 comprises two pairs ofco-acting top and bottom wheels that are provided along opposite sideedges of web 16. A topmost wheel of each pair comprises a follower wheel76 and a bottom-most wheel of each pair comprises a drive wheel 78 thatis actuated and driven by a servo motor. As was the case with driverassembly 64, drive wheels 78 of drive wheel assembly 66 are driven usinga common servo motor, a splined drive shaft, splined drive wheels, and apair of correspondingly splined drive rollers attached to each drivewheel 78. Accordingly, actuation of drive wheel assembly 66 viacontroller 18 is operative to intermittently deliver rows of articles 14into trim press 12 in cooperation with drive wheel assembly 64.

[0038] As shown in FIG. 1, drive wheel assembly 64 comprises a dualservo motor driven roller feed assembly referred to herein as servo pickassembly 60. According to one construction, follower wheels 70 and 76are each formed from a high density polyethylene (HDPE) plasticmaterial. Also according to one construction, drive wheels 72 and 78 areeach formed from an anodized aluminum material having a knurled radialouter surface that coacts with web 16.

[0039] Additionally, web 16 is delivered through an oven and athermoforming machine using a web conveyor, upstream of trim press 12.One exemplary detailed construction for a web conveyor is disclosed inU.S. Pat. No. 5,806,745, herein incorporated by reference.

[0040] According to one construction, article registration is carriedout by adjusting the operation of conveyor 20 using controller 18 inorder to adjust the advancement and positioning of individual articlesbetween punch plate 30 and die plate 32.

[0041] However, in some cases, it is very difficult to adjust the set-upand component positioning for a web conveyor in order to accurately andprecisely deliver articles 14 between punch plate 30 and die plate 32.Hence, article registration implemented solely using conveyor set-up andcontrol does not always sever such articles in a sufficiently uniformand accurate manner. Furthermore, there are limitations to the accuracywith which a servo motor can drive conveyor assembly 20, and therefore,in the ability of such servo motors to accurately place articles 14between punch plate 30 and die plate 32. Oftentimes, it is the case thatarticles 14 are off by several millimeters, which can produce anundesirable effect, particularly where article 14 is of a complicatedshape, or article 14 comprises a foldable container having a hinge whichrequires a high degree of accuracy in forming and severing thereof inorder to accurately place the hinge.

[0042] Accordingly, an article registration device (not shown) canalternatively be added to punch plate 30 and die plate 32 in order toprovide an enhanced ability to accurately register articles 14 betweenpunch plate 30 and die plate 32 when severing such articles 14 from web16. One suitable article registration device is disclosed in Applicant'spending U.S. patent application Ser. No. 09/575,783, now U.S. Pat. No.6,435,067B1, entitled “Apparatus and Method for Registering ArticlesDuring a Web Processing Operation”, naming the inventor as Jere F.Irwin, and herein incorporated by reference.

[0043] After severing articles 14 from web 16, the scrap web isdelivered into a comminuting apparatus (not shown) that is provideddirectly beneath punch plate 30 and die plate 32. Several differentcomminuting apparatuses suitable for grinding up the resulting scrap webare disclosed in U.S. Pat. Nos. 4,687,144; 5,836,527; 5,860,607; and5,893,523, each herein incorporated by reference. Scrap web 74 isaccordingly forwarded into such a recycling, pulverizing machine wherethe scrap web is shredded and then later recycled to form a new web ofthermoformable plastic material.

[0044] Details of one exemplary thermoforming machine suitable forforming articles 14 within web 16 are disclosed in U.S. Pat. No.5,773,540. U.S. Pat. No. 5,773,540 is herein incorporated by reference.

[0045] Control system 18 of FIG. 1 comprises a controller having controlcircuitry 68 such as processing circuitry and memory. According to oneconstruction, processing circuitry is provided by a central processingunit (CPU). According to another construction, processing circuitry isprovided by a microcontroller which cooperates to form the controller.It is understood that memory is operative to store software subroutinesthat are retrieved and implemented on the processing circuitry in orderto impart motion control functionality by way of controller 18 to trimpress 12 and conveyor 20.

[0046] As shown in FIG. 1, control system 18 is operative to generatecontrol signals that direct operation of servo drive motor 31 thatdrives crank arm assemblies 34-37 and thereby imparts reciprocation tomovable platen 26. Servo drive motor 31 comprises a highly accuratecomputerized servo motor and servo drive which can be accurately drivenby control system 18. In operation, servo drive motor 31 drives a gearbox or transfer case 33 that imparts a rotary motion to each of crankarm assemblies 34-37. Furthermore, control system 18 is operative todeliver a control signal to the servo drive motors of servo pickassembly 60 and servo helper assembly 62 that advances article conveyor20. Additionally, control system 18 receives an input signal from anarticle detector 80 provided on treadle 10 for detecting the location ofarticles being moved by treadle 10 into trim press 12.

[0047] As shown in FIGS. 1 and 3, treadle 10 is driven via a kinematiclinkage 87 by movable platen 26, wherein movable platen 26 is driven viamotor 31. Accordingly, kinematic linkage 87 causes frame 52 of treadle10 to reciprocate back and forth in relation to the movement of movableplaten 26, relative to stationary platen 28. Kinematic linkage 87includes a rocker arm 89 which has a fixed rotatable pivot attached toframe 42.

[0048] As shown in FIG. 2, a partial view of the treadle illustratesimportant components relating to Applicant's invention; namely, theframe of treadle 10 includes a pair of side plates 88 (only oneillustrated herein) which are joined together by three tie rods 90. Aprimary guide member 82 is provided in proximate association with webguide plate, or web guide member, 100. A secondary guide member 84 isspaced substantially further apart from plate 100 than is primary guidemember 82. Secondary guide member 84 is provided principally to serve asa gross alignment structure which is received between adjacent rows ofarticles so as to grossly induce alignment of articles with web guideplate 100 relative to article apertures 102.

[0049] Primary guide member 82 and secondary guide member 84 eachinclude an attachment plate 94 having a quick release adjustment collar92 which includes a threaded, rotatable lock arm that enables clampingand unclamping of adjustment collar 92 along a central one of tire rods90. In this manner, primary guide member 82 and secondary guide member84 can be quickly and easily laterally adjusted in position relative toweb guide plate 100 so as to accommodate changes to different dieconfigurations.

[0050] Primary guide member 82 further comprises a clamp bar 96 affixedwith fasteners to attachment plate 94, and further affixed to support aguide strip 98 that is nested in proximate relation relative to asurface of guide plate 100. According to one construction, a gap existsbetween guide strip 98 and web guide plate 100 somewhere in the range of1-3.5 thicknesses of a web of material which is to be received andprocessed therebetween.

[0051] Secondary guide member 84 further comprises a clamp bar 96carried by attachment plate 94 and further supporting a guide strip 198.Guide strip 198 is constructed so as to provide a substantially greateramount of clearance between guide strip 198 and web guide plate 100 thanis provided between guide strip 98 and web guide plate 100. Accordingly,guide strip 198 is spaced apart from plate 100 at least 3.5 thicknessesof a web which is to be received and processed therethrough. Preferably,web guide plate 100 is provided within a range of 3.5 to 10 thicknesses(or more) of a web of material. In this manner, delivery of a web andarticles there along is principally guided by guide strip 98, and littleor no contact occurs between guide strip 198 and such web during aprocessing operation.

[0052] Additionally, as shown in FIG. 2, article detector 80 comprisesan optical emitter 104 carried by attachment plate 94 of primary guidemember 82 and a detector 106 carried by attachment plate 94 of secondaryguide member 84. A light beam 108 is generated from emitter 104 andreceived at detector 106. The presentment of an article between primaryguide member 82 and secondary guide member 84 causes interruption oflight beam 108 which is detected at the control system 18 (of FIG. 1).Accordingly, the positioning of articles can be readily determinedutilizing the control system and article detector 80 pursuant toApplicant's invention.

[0053] As additionally illustrated in FIG. 2, servo pick assembly 60comprises a pair of drive wheels 72 and follower wheels 70 alongopposite edges of a web of material which is processed therebetween.Follower wheels 70 are retracted with each utilizing a knock levermechanism 110 as treadle 10 is moved towards stationary platen 24 (ofFIG. 1). Accordingly, drive wheels 72 and follower wheels 70 areseparated just prior to severing of an article so that further alignmentcan occur via coaction of the die surface and/or an alignment structurewhich further laterally positions articles relative to associatedpunches and dies of the trim press.

[0054] As shown in FIG. 2, knock mechanism 110 comprises a kinematiclinkage having a center pivot point and a lever arm at one end thatcontacts stationary platen 28 as treadle 10 is moved there againstduring a severing operation. The other end of mechanism 110 carriesfollower wheel 70. Such contact rotates follower wheel 70 away fromdrive wheel 72 so as to open up a gap therebetween, thereby releasingrespective edges of the web to ensure further centering. Furthercentering relies on contour features of the individual punches 22coacting in combination with the shape of in-molded articles in the webto laterally further align such articles relative to each respectivepunch and die, according to one construction.

[0055]FIG. 3 illustrates in simplified form the arrangement of punchplate 30, web guide plate 100 (configured here as a stripper plate), anddie plate 32. Controller 18 includes control circuitry 68 which isoperative to control the servo motors which activate drive wheels 72.Follower wheels 70 are retractable in response to actuation of knockmechanism 110, illustrated in FIG. 2.

[0056] As shown in FIG. 3, guide strip 98 serves principally to guideweb 16 and articles 14 against plate 100. In contrast, guide strip 198is spaced a significant distance away from plate 100, and principallyserves to support detector 106. However, guide strip 198 also serves togrossly retain web 16 into position along plate 100 in the event thatweb 16 becomes suddenly significantly misaligned. Accordingly, undernormal operating conditions, guide strip 98 serves as the only principalguide for retaining web 16 in close proximity against web guide plate100. Accordingly, frictional forces therebetween are significantlyreduced. Furthermore, emitter 104 and detector 106 further serve todetect the location and positioning of articles 14 as they are deliveredvia drive wheel 72 (and associated servo motor). All such control ischoreographed utilizing controller 18 as well as a feedback signal fromdetector 106.

[0057] As shown in FIG. 3, punch plate 30 includes a plurality ofpunches 22, each supported on axially guided springs. The springsfacilitate interdigitation and lateral alignment with appropriatelyconfigured articles 14, and compress and coact with punch plate 30during final severing against die plate 32 through the holes withinplate 100.

[0058] As shown in FIG. 3, follower wheels 70 are caused to open (orretract) away from drive wheel 72 via action of knock lever mechanisms110 (see FIG. 2). Such retraction further facilitates lateral alignmentof web 16 and articles 14 relative to punches 22 and dies within dieplate 32.

[0059] Also illustrated in FIG. 3, guide strip 98 is shown in closeproximity with web guide plate, or web guide member, 100. In contrast,guide strip 198 is shown spaced relatively far apart from plate 100.

[0060]FIG. 4 illustrates an enlarged partial view corresponding withline 3-3 of FIG. 2, the relative positioning of guide strip 98 ofprimary guide member 82 (see FIG. 2) relative to web guide plate 100.Guide strip 98 is provided in relatively close proximity with plate 100so as to ensure alignment and positioning of web 16 (and articles 14)relative to articles apertures 102 in plate 100.

[0061] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

The invention claimed is:
 1. A method for delivering web-supportedarticles between dies and punches of a trim press, comprising: providinga treadle having an article detector; while moving the web and thearticles, guiding the web and the articles along the web and between apair of the articles each provided in one of a pair of adjacent rowsthat extend along a travel path direction; detecting location of anarticle in the web using the article detector; and in response todetecting the location of the article, controllably moving the web toposition the article between a corresponding punch and die of the trimpress.
 2. The method of claim 1, wherein the step of detecting locationcomprises optically detecting movement of an article relative to thearticle detector.
 3. The method of claim 1, wherein the step ofdetecting location of an article comprises optically detecting aprotuberance in the web.
 4. The method of claim 3, wherein theprotuberance is an article embedded in a web.
 5. A method for deliveringa web of material having articles formed therein between a die and punchof a trim press, the method comprising: guiding the web between the dieand the punch, the die and the punch being provided in a travel path ofthe web; providing a treadle having an article detector, the treadlebeing configured to move relative to the die and the punch; detecting alocation of an article in the web using the article detector; andcontrollably moving the web, in response to the detecting, to positionthe article between the punch and the die to perform severing andtrimming of the article.
 6. The method of claim 5, wherein the treadleis further configured to convey the web having the articles between thedie and the punch.
 7. The method of claim 5, wherein the guidingcomprises: guiding the web and the articles using a servo helperassembly and a servo pick assembly; measuring an amount of feed impartedby the servo helper assembly relative to an amount of feed imparted bythe servo pick assembly; and synchronizing operation of the servo helperassembly in relation to operation of the servo pick assembly.
 8. Themethod of claim 7, wherein the guiding further comprises: providing aphoto proximity switch on a guide member and beneath one edge of the webto detect proximity of the web in relation to the guide member; andperforming the synchronizing further to detecting the proximity of theweb in relation to the guide member.
 9. The method of claim 8, whereinthe synchronizing is performed to produce an increased throughput rateof the web conveyed between the die and the punch of the trim press. 10.The method of claim 8, wherein delivery speed of the servo helperassembly relative to the servo pick assembly is controllably regulatedby a control system in response to a signal detected by the photoproximity switch.
 11. The method of claim 10, wherein the control systemis configured to move a follower wheel away from a drive wheel for apredetermined amount of time, while the trim press is in an open stateand not performing a trimming operation, to enable realignment of theweb, the follower wheel and the drive wheel being included in the servopick assembly.
 12. The method of claim 11, wherein the realignment ofthe web comprises adjusting spacing of the web between the servo helperassembly and the servo pick assembly prior to performing the trimmingoperation.
 13. The method of claim 5, wherein the detecting comprisesoptically detecting movement of an article relative to the articledetector.
 14. The method of claim 5, wherein the detecting comprisesoptically detecting a protuberance in the web.
 15. The method of claim14, wherein the protuberance is an article embedded in a web.
 16. Amethod for delivering a web of material having articles formed thereinbetween a die and punch of a trim press, the method comprising: guidingthe web between the die and the punch; providing and configuring atreadle to move relative to the die and the punch; detecting a locationof an article in the web; and controllably moving the web, in responseto the detecting, to position the article between the punch and the dieto perform severing and trimming of the article.
 17. The method of claim16, further comprising providing the die and the punch in a travel pathof the web.
 18. The method of claim 16, wherein the providing comprisesproviding the treadle having an article detector, and the detecting stepcomprises detecting a location of the article using the articledetector.
 19. The method of claim 18, wherein controllably moving theweb comprises synchronizing movement of the web to produce an increasedthroughput rate of the web conveyed between the die and the punch of thetrim press.
 20. The method of claim 19, wherein movement of the web iscontrollably regulated by a control system in response to a signaldetected by the article detector.
 21. The method of claim 20, whereinthe control system is configured to move a follower wheel away from adrive wheel for a predetermined amount of time, while the trim press isin an open state and not performing a trimming operation, to enablerealignment of the web, and the follower wheel and the drive wheel areconfigured in a closed state to support movement of the web.